spitting food out

So my little man is 1 on the 23rd and for the past week or so he's been spitting out food or just refusing everything I give him. The most I can get him to have is a few mouthfuls and then he starts letting the food fall out of his mouth! I just feel like he's not getting enough food and he only has 12 oz of milk a day so that can't be filling him. Has anyone else been experiencing this? He has recently had two new teether through but I don't think it's that that's causing the refusal of food!